scholarly journals Water quality impact from shrimp farming effluents in a tropical estuary

Author(s):  
E. G. Bull ◽  
C. de L. da N. Cunha ◽  
A. C. Scudelari

Abstract Shrimp farms cause environmental impacts in coastal ecosystems, compromising water quality by discharging effluents rich in nutrients and organic matter. The impacts of shrimp farming are often investigated by the unit effect of a farm. In this study, a harvest time series generator is used to analyze the impact of the synergistic effect of several shrimp farm harvests in a tropical estuary. Two other scenarios with harvests concentrated during spring and neap tides were also analyzed, showing waste management techniques that can reduce the impact of shrimp aquaculture on coastal areas. A hydrodynamic circulation and water quality model were implemented to evaluate the dispersion of pollutants using different discharge combinations. The harvesting scenarios were compared to a scenario without the activity. Results indicate that shrimp farming is not the main anthropogenic source of pollution in the estuary studied. There were no significant differences in the average and maximum variations in nutrient and organic matter concentrations between the different management techniques.

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Mansoor A. Baluch ◽  
Hashim Nisar Hashmi

Water quality of the Indus River around the upper basin and the main river was evaluated with the help of statistical analysis. In order to analyze the similarities and dissimilarities for identifying the spatial variations in water quality of the Indus River and sources of contamination, multivariate statistical analysis, i.e., principle component analysis (PCA), cluster analysis, and descriptive analysis, was done. Data of 8 physicochemical quality parameters from 64 sampling stations belonging to 6 regions (labeled as M1, M2, M3, M4, M5, and M6) were used for analysis. The parameters used for assessing the water quality were pH, dissolved oxygen (DO), oxygen reducing potential (ORP), electrical conductivity (EC), total dissolved solids (TDS), salinity (%), and concentration of arsenic (As) and lead (Pb), respectively. PCA assisted in extracting and recognizing the responsible variation factors of water quality over the region, and the results showed three underlying factors including anthropogenic source pollution along with runoff due to rain and soil erosion were responsible for explaining the 93.87% of total variance. The parameters which were significantly influenced by anthropogenic impact are DO, EC, TDS (negative), and concentration of Pb (positive), while the concentration of As, % salinity, and ORP are affected by erosion and runoff due to rain. The worst pollution situation for regions M1 and M6 was due to the concentration of As which was approximately 400 μg/l (i.e., 40 times higher than minimum WHO recommendation). Furthermore, the results also indicated that, in the Indus River, three monitoring stations and five quality parameters are sufficient to have a reasonable confidence about the quality of water in this most important reserve of Pakistan.


1990 ◽  
Vol 22 (5) ◽  
pp. 69-78 ◽  
Author(s):  
D. Müller ◽  
V. Kirchesch

The construction of two or three impounding dams in the remaining freely flowing reach (73 km) of the Danube is under discussion. The purpose of these impoundments is to guarantee a minimum navigable depth of 3 m needed for modern cargo ships and to produce electric power. The impact of these developments is discussed on the basis of experience with similar impoundments further upstream and of the results from water quality model calculations. The mathematical model used is of the deterministic type, calculating the growth of slowly-growing organisms (nitrifying bacteria, algae and zooplanktons) according to MONOD and MICHAELIS-MENTEN. Compared with impoundments on other German rivers or the Iron Gate impoundments on the Danube, the effect of the impoundments under discussion on water quality parameters is likely to be fairly small, reflecting the slight changes in morphology which would be necessary for attaining the water depth required. Therefore, the more important effects of these developments would be the changes in the ecologic situation at the river bed and near the banks of the river.


2010 ◽  
Vol 61 (9) ◽  
pp. 2381-2390 ◽  
Author(s):  
Gabriele Freni ◽  
Giorgio Mannina ◽  
Gaspare Viviani

The objective of this paper is the definition of a methodology to evaluate the impact of the temporal resolution of rainfall measurements in urban drainage modelling applications. More specifically the effect of the temporal resolution on urban water quality modelling is detected analysing the uncertainty of the response of rainfall–runoff modelling. Analyses have been carried out using historical rainfall–discharge data collected for the Fossolo catchment (Bologna, Italy). According to the methodology, the historical rainfall data are taken as a reference, and resampled data have been obtained through a rescaling procedure with variable temporal windows. The shape comparison between ‘true’ and rescaled rainfall data has been carried out using a non-dimensional accuracy index. Monte Carlo simulations have been carried out applying a parsimonious urban water quality model, using the recorded data and the resampled events. The results of the simulations were used to derive the cumulative probabilities of quantity and quality model outputs (peak discharges, flow volume, peak concentrations and pollutant mass) conditioned on the observation according to the GLUE (Generalized Likelihood Uncertainty Estimation) methodology. The results showed that when coarser rainfall information is available, the model calibration process is still efficient even if modelling uncertainty progressively increases especially with regards to water quality aspects.


2015 ◽  
Vol 46 (4) ◽  
pp. 291-335 ◽  
Author(s):  
M. Pivokonsky ◽  
J. Naceradska ◽  
I. Kopecka ◽  
M. Baresova ◽  
B. Jefferson ◽  
...  

Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 189
Author(s):  
Geovanni Teran-Velasquez ◽  
Björn Helm ◽  
Peter Krebs

The fluvial nitrogen dynamics at locations around weirs are still rarely studied in detail. Eulerian data, often used by conventional river monitoring and modelling approaches, lags the spatial resolution for an unambiguous representation. With the aim to address this knowledge gap, the present study applies a coupled 1D hydrodynamic–water quality model to a 26.9 km stretch of an upland river. Tailored simulations were performed for river sections with water retention and free-flow conditions to quantify the weirs’ influences on nitrogen dynamics. The water quality data were sampled with Eulerian and Lagrangian strategies. Despite the limitations in terms of required spatial discretization and simulation time, refined model calibrations with high spatiotemporal resolution corroborated the high ammonification rates (0.015 d−1) on river sections without weirs and high nitrification rates (0.17 d−1 ammonium to nitrate, 0.78 d−1 nitrate to nitrite) on river sections with weirs. Additionally, using estimations of denitrification based on typical values for riverbed sediment as a reference, we could demonstrate that in our case study, weirs can improve denitrification substantially. The produced backwater lengths can induce a means of additional nitrogen removal of 0.2-ton d−1 (10.9%) during warm and low-flow periods.


2005 ◽  
Vol 40 (1) ◽  
pp. 59-70 ◽  
Author(s):  
Karl-Erich Lindenschmidt ◽  
Jan Rauberg ◽  
Fred B. Hesser

Abstract This paper illustrates the coupling of water quality model components in High Level Architecture (HLA), a computer architecture for constructing distributed simulations. HLA facilitates interoperability among different simulations and simulation types and promotes reuse of simulation software modules. It was originally developed for military applications but the platform is finding increasing applicability for civilian purposes. The models from the Water Quality Analysis Simulation Program (WASP5) were implemented in HLA to extend its Monte Carlo uncertainty analysis capabilities. The models include DYNHYD (hydrodynamics), EUTRO (phytoplankton and nutrient dynamics) and TOXI (sediment and micropollutant transport). The uncertainty analysis investigated the impact of errors in the hydrodynamic parameters (weir discharge and roughness coefficients) and boundary conditions (upstream and tributary discharge) on the uncertainty in the water quality output variables. It was found that the contribution of the hydrodynamic parameter error to the water quality output uncertainty is comparable to that obtained from the error in the water quality parameters. The error in the boundary condition input data is also an important contributor to model uncertainty.


2003 ◽  
Vol 48 (10) ◽  
pp. 151-158 ◽  
Author(s):  
Y.-J. Chen ◽  
S.-C. Wu

It was found that the increase of sediment P release in the anoxic state associated with the density current initiated by the cold front in the winter was the cause of the deterioration of the water quality of the subtropical, noncalcareous and deep reservoir, Feitsui Reservoir, in recent years. A mathematical model including the analytical solutions of the transport of the density current combined with a simple 2-layered water quality model has been established, describing the hydrodynamics and the water quality variation of the reservoir well. The continued sediment release of P in the anoxic state (from October to March) is an important P source and should be carefully assessed and controlled to reduce the impact of the internal loading of P incorporated with the density current on the water quality in future years.


1994 ◽  
Vol 29 (3) ◽  
pp. 137-139 ◽  
Author(s):  
P. R. G. Kramer ◽  
Th P. Traas ◽  
T. Aldenberg ◽  
M. B. de Vries

An integrated approach concerning the causality chain of emission, distribution and effects of toxicants was chosen to analyze the influence of pollution and the impact of historical and future measures in the Rhine basin. All major sources have been quantified and the distribution of nutrients and toxicants is determined by means of a dynamic model. A contaminant accumulation model is linked to this water quality model in order to assess the ecological effects of the compounds in specific areas. This modelling framework is used to analyze effects of cadmium on the foodweb found in Rhine sedimentation areas. Model predictions show that No Observed Effect Concentration (NOEC) levels for cadmium in algae and small molluscs are not exceeded.


Sign in / Sign up

Export Citation Format

Share Document